Row about doctor’s deal, perhaps (6)
I believe the answer is:
timber
'deal perhaps' is the definition.
(deal is a kind of timber)
'row about doctor's' is the wordplay.
'row' becomes 'tier' (a tier is a row of things).
'about' means one lot of letters goes inside another.
'doctor' becomes 'mb' (Bachelor of Medicine).
'tier' going around 'mb' is 'TIMBER'.
(Other definitions for timber that I've seen before include "Trees suitable for building or carpentry" , "Wood (that may be shivered?)" , "Deal possibly" , "The tree's falling!" , "Wood for building, etc" .)